Over the weekend, people shopping on Amazon thought they’d hit the jackpot: popular recent PC games like Frostpunk and Surviving Mars for the price of a cup of coffee. Problem: these copies were pirated.

Word of the dubious deals first got out in a Reddit thread on Saturday. “I think this is a screw up from them [Amazon], I dunno if someone wants to try it though,” read the thread, which linked to a $2.99 copy of Frostpunkwhose seller was listed as Amazon Digital Services. The ice-encrusted management game usually sells for $29.99. Other users surfaced similar listings, like Surviving Mars—which usually goes for $39.99—for $3.99.

One user, CodependentlyWealthy, did some sleuthing. “I decided to pay $3 to play detective,” they said of Frostpunk. “It’s piracy. Someone took the GOG version of the game, repackaged it with their [sic] own installer signed and published by ‘Ace Media Group LLC’ and submitted it to Amazon. The installer looks fairly legit but the uninstaller doesn’t work. They left GOG-specific metadata files and Galaxy64.dll (for GOG Galaxy client integration) in the install dir.”

GOG is a PC gaming platform whose greatest claim to fame is its lack of DRM. On one hand, it’s nice to be able to purchase games sans invasive software riding in the passenger seat, but it leaves wiggle room for exploitation. In this case, it seems that the pirates took GOG copies of games, added their own custom installer, and claimed them as their own.

Users reviews of these game listings include similar claims. The offers are no marked as “currently unavailable” and can no longer be purchased. Surviving Mars’ developers, meanwhile, took to Twitter to address the issue:

“This is not a sale we’ve approved and we’re suspect of the legality of it,” they wrote. “We can confirm that no updates will work with it and we’d advise steering clear of it.”

Posters on gaming message board Resetera point out that Amazon has failed to police video game listings before. Last October, fantasy RPG Lords of Xulima popped up on the all-consuming mega-store for $1.99. At the time, the game’s developer said it was trying to get the listing removed, but Amazon’s demands made that difficult.

“We are trying to remove that seller, but Amazon seems to require lots of documents from us,” Xulima developer Numantian Games wrote in its Steam forum. “It seems that you can sell a pirated game without any problem, but if the owners complain about it, they have to present a lot of very complex documents. What a shame.”